In the present day operating environment, exploratory development companies operating in their search for new sites to obtain oil in the ocean floor, drill pilot wells at many sub sea sites in search of and to verify that the site has productive capability.
To do this, they need to establish that the oil fields which they are screening can provide oil quantities necessary to establish whether the site is commercially feasible. Thus, they generally find necessary to drill a series of exploratory drill sites to determine the size and magnitude of the field they are working in. The initial operations take care of extracting and eliminating the so called mud, which is the assemblage of drilling fluids and cuttings. This is necessary and they need to determine the problems they would encounter to develop this new oil site, which is accomplished by use of either a drill ship or a movable drill platform that they move over and about the potential exploratory site for pilot drilling of wells. To do this as the operators drill into the ocean floor, they insert a riser pipe in the drill hole as they drill deeper and deeper to find the cavity of oil they are searching for. When they strike a rich quantity of oil, they plug the new well site up and drill new exploratory test holes in the surrounding area of the ocean floor, to determine the magnitude of the oil field that they have found. To prevent loss of oil through these newly drilled exploratory wells, as they finish drilling at each test site, they plug these pilot wells with a mix of cement that is pumped down the riser pipe and generally attempts to seal each test well so that they can return at a later date and redrill at this newly discovered oil source. At this oil source, when the operators are ready to convert it over into a producing well, they have to either drill additional new wells, or drill down through the concrete plug that they had put in the pilot well and had previously capped.
When the work is in shallow depths, the establishment of these test wells presently are plugged using this pump down cement in the riser to stop the flow of oil.
When intense pressure of a well is encountered in the riser, at the riser surface, and the ocean floor site is penetrated, the oil and gas, due to pressure, escape up the well and the operators are forced to quickly cap the well in order not to lose oil and gas under pressure into the ocean and contaminate the ocean water surrounding the new well site.
As the operators expand their locations for these test well sites, they are obliged to move further and further away from land, looking for richer fields of oil on the ocean floor and as they establish these exploratory new wells, at these sites they encounter increased pressure, the deeper they drill and further outward they reach in the ocean. What was feasible originally for the establishment and plugging of these test well sites, in shallow water, has become more difficult when encountering extremely high pressures, and the methods for plugging these wells have become risky and coping with this immense high pressure, is the reason why these previous methods of plugging wells have now been considered dangerous and almost impossible to accomplish. Because of this condition, there have been times when accidents have happened at these well sites resulting in great quantities of oil dispersed in the ocean. In a few occasions, operating personal lost their lives while closing down the well sites.
There is an urgent need for a new method and new equipment to operate and provide a means to capture the oil flow encountered in normal situations or in emergencies at over flowed well sites. The present invention does neither cover any procedures associated with the process of drilling holes in the ocean floor, nor the problems of discharging the fluids and cuttings that are the residue of drilling. This invention plugs the wells' riser after the well has been drilled, by removal of the drill and insertion of this stop flow plug containment system. This invention is a new method and new equipment to operate and provide a means to capture the oil/flow encountered at the test well sites. In fact, the system and the mechanism of this invention do not fight the high pressure of deep seas; on the contrary, such high pressure is used to actuate and close down the valve blocking the escape of precious oil and gas.
In the searches reviewed regarding existing possible conflicting patents, most of the related patents concern primarily the drilling function, which do not apply to the present invention. That is the case of the following patents:
U.S. Pat. No. 6,668,943 B1, of L. Donald Maus et al, for “Method and Apparatus for Controlling Pressure And Detecting Well Control Problems During Drilling of an Offshore Well Using a Gas-Lifted Riser”,
U.S. Pat. No. 5,184,686, of Gonzalez, for a system to avoid washout, however that system requires using two different size drillings risers.
U.S. Pat. No. 5,727,640, of Svein Gleditsch (Norway), for “Deep Water Slim Drilling System”
U.S. Pat. No. 4,813,495, of Colin P. Leach, for “Method and Apparatus for Deep Water Drilling
In turn, we will cite some patents which do not mention expressly in their titles their association to the drilling function but, in fact, they are related thereto, i.e., they are part of the deep ocean well drilling:
U.S. Pat. No. 7,121,346 B2, of Danny K. Wolff et al., for “Intervention Spool for Subsea Use” is a multiplicity of valves in sequence to close-out the flow which is a conventional method of flow control, and that does not apply to the present invention
U.S. Pat. No. 6,802,379 B2, of Dawson et al—for “Liquid Lift Method for Drilling Tisers”, is a patent related to drilling through the risers below the body of water and injecting fluids into the wells riser, which does not apply to the present invention
Pat No. US 2009/0126798 A1, of Sam Mather (GB) for “Autonomous Shut-off Valve System”, this system uses a fluid powered valve actuator and multiple pressure sensors to close the flow, which does not apply to the present invention.
Pat. No. US 2005/0284639 A1, of Larry E. Reimert, for “Pressure Compensated Flow Shut-Off Sleeve for Wellhead and Subsea Well Assembly Including Same”, where the shutoff function is controlled by a movable sleeve which opens and closes flow ports, which does not apply to the present invention.
U.S. Pat. No. 3,783,887, of Akira Shojl (JP), for “Self-Closing Valve Device in a Piping System of Fluids”, that comprises a valve chamber, an inlet pipe for a fluid connected to a control cylinder an outlet pipe that operates a piston by use of a permanent magnet that seals the passage with a globe, and it does not apply to the present invention.
U.S. Pat. No. 2,570,372, of Tom E. Parrish, for “Automatic Shutoff Valve”, the operational functions are conducted in the mud at the drilling point of the well and uses a float to shutoff the fluid in the pipe, and this does not apply to the present invention.
U.S. Pat. No. 4,126,183, of Raymond W. Walker for “Offshore Well Apparatus with a Protected Production System”, that includes a platform means at the sea surface and a complex well template means beneath the platform means, which does not apply to our invention.
U.S. Pat. No. 6,401,823 B, is a part of the drilling operations to control the mud circulating system in different stages, shutting off the flow with a piston that closes off ports driven by a spring operated piston in a cylinder that opens and closes ports in the valve, and it does not apply to the present invention.
U.S. Pat. No. 4,291,772, of Beynet, for “Deep Water String Shut-Off” which operates controlling the flow of the mud during drilling, using a spring for different drilling conditions, and it does not apply to the present invention.
The system of pumping cement down the riser is next to impossible where well pressures are up in the thousands. A recent well site, where an accident occurred, caused a considerable number of lives lost, because the oil pressure encountered was greater than 5,000 psi. Tremendous quantities of oil leaked out through the riser pipe to the surface of the ocean and could not be captured for a long period of time. As a result, contaminated beaches and vast areas of the ocean suffered a catastrophic ecological disaster. The present new invention has addressed this problem and provides a new method for capping an ocean drilled well site, minimizing the loss of oil into the ocean. To cap a newly drilled well and install its riser pipe, presently the cap function is accomplished up at the surface and as a part of the operation and procedure, must cope with the internal pressures coming up the newly inserted riser pipe. Once drilled into a new site, the riser pipe releases this intense oil and gas pressure that the operator must cope with. In fact, when the pressures are so intense and uncontrollable, sometimes even riser pipe has been bent and cut in order to stop and seal the upward pressure flow. Fighting to suppress the intense pressure of oil and gas coming up the riser pipe, and the urgent need to cap this well riser pipe at the surface, the existing method of pumping fluid cement mix down the riser, in large quantities, to stop and cut off the flow, is well known as very difficult and should be considered not the most efficient way to solve the capping problem.
The present invention addresses the problem differently, aware of the fact that there is an intense unknown quantity of oil and gas that must be quickly contained against high pressure to accomplish a successful capping and cutoff of the volumes of gas and oil escaping into the ocean
The present invention uses the pressure available to stop the escaping oil flow and to seal the riser. Applying such logic, this invention is designed to insert in the riser pipe a stoppage plug as a shut off barrier for this oil flow. This invention is a valve assembly attached to the present drill string tool, to be used after all drilling is completed. One or more electronic sensors are contained in the valve in order to monitor the stop flow function and conveys the conditions to an electronic operators' display, for operational control and monitoring.
The present invention accepts the fact that there is unknown volumes and quantities of pressure, and the sealing capping function there must be acknowledged and worked with, so that the flow can be captured and stopped. Since it is there, then the solution of the problem should be reversed and the pressure should be used to help and aid the capping problem
The sensor, or sensors, attached to the valve at the end of the drill string tool send data to the operator's remote electronic display panel who will act according to where the oil/flow should be stopped, as well as all pertinent action to be taken.
The drill string tool operation can lower the containment valve and close out the flow with the valve from above, at—or below—the ocean surface. In short, we are closing the well, by plugging the well flow with the well own pressure.